Device for compressing tires for shipment in containers

ABSTRACT

A device for compressing tires and other compressible items in a shipping container comprises a support frame 22 attached to the lift end of a forklift. A fixture 20 is attached to and moves vertically with the support frame. The fixture comprises a horizontal compression platen 30. A vertical pusher plate 50 extends above and below the platen. The upper pusher plate 53, which is above the platen, can fold down so that the platen can be brought near the ceiling of a shipping container above a stack of tires. The fixture weighs enough to compress tires stacked below the compression platen. Additional tires are stacked above the platen and compressed tires. The upper pusher plate is then folded up, against the tires. Two hydraulic cylinders push the pusher plate away from the support frame to pull the platen from between the tires.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a device for compressing a load oftires or other compressible material for improving the load density ofcompressible materials loaded in a shipping container.

2. Related Application

This application is a continuation of U.S. application Ser. No.08/299,742, filed Sep. 1, 1994, now Pat. No. 5,544,578.

3. State of the Art

Tires must be shipped from factories to warehouses and distributors.Typical load densities for tires shipped in a freight container arequite low. That is, although a passenger tire may be 2' (0.3 m) (metricequivalents are approximate) in diameter and 6" (15 cm) wide, the tirevolume is mostly air.

How tires are loaded in the container affects the amount of unused spacein a load of tires. It is generally believed that loading tires in aherringbone pattern maximizes load density. In a herringbone pattern,which FIG. 2 shows, a first tire is either laid flat (i.e., horizontal)or propped at an angle against the side wall in the front corner of ashipping container floor (as FIG. 2 shows). If the first tire is laidflat, the next tire leans against the first tire at an angle. If thefirst tire is propped at an angle against the wall, the next tire isplaced parallel to the first. The third tire is then placed parallel tothe second, and the process is repeated until the last tire reaches theother front corner to complete a first row of tires.

A second row is mounted above the first row, but each tire in the secondrow is angled in the opposite direction to the angle of the tires in thefirst row. Additional rows are added until the load reaches the top ofthe container, thus completing a stack or column. Next, a second rowbehind the first row is started, and a new herringbone pattern is made.This continues with piled rows continuing to the back of the containeruntil the container is filled.

U.S. Pat. No. 4,777,781 (1988) and U.S. Pat. No. 4,920,729 (1990), bothto Doster et al., disclose devices for compressing tires vertically toimprove load density. Both devices install themselves in place beforeany tires are stacked in the shipping container. When the herringbonepattern reaches about 2/3 or 3/4 to the top of the container, ahydraulic ram puches or pulls a plate over the stack down on the top rowof tires of one stack. The plate thus compresses the rows below.

In the earlier patent, the compression plate is first raised to theceiling after the tug is clamped to the ceiling but before any tires arestacked in the container. The later patent is mounted on a machine thatis not a forklift, tug or other standard machine. In both devices, whilethe stack of tires remain compressed, other tires are loaded above theplate. The hydraulics then push the plate (or what the patent calls the"wedge") upward, which partially relieves some of the compression on thetires of the stack below the wedge and simultaneously compressespartially the tires above the wedge. When the load above and below isapproximately equal, the wedge is removed from between two rows. Apusher next to the wedge holds the rows above and below the wedge whilethe wedge is removed. The process is repeated for all subsequent stacks.

One problem of the just-described device is the use of a two way driverfor moving the wedge up and down. Because the system uses hydraulics tocompress the tires below the wedge, the wedge must push against thecompressed tires. Those compressed tires exert an opposite force on thewedge. To prevent that opposite force from lifting the wedge and theentire device, the device needs an overhead frame to contact thecontainer ceiling for supporting the device between the container floorand ceiling. The overhead frame prevents the tires from pushing theentire device upward. The mechanism that moves the overhead frameagainst the ceiling complicates the device, however. Also, havingtwo-way, hydraulically driven movement makes this device more complexand subject to increased maintenance expenses.

Further, the amount that the device compresses tires below the wedge canvary with different operators. An operator using the device's hydraulicsmay over- or under-compress the tires. Over-compression may damagetires. Too little compression results in insufficient volume reduction.

When the wedge of the prior art device is removed from the rows oftires, there is a tendency for the tire stack to bow outward or fallover. The prior art holds the rows of tires immediately above and belowthe wedge as the wedge is removed, but nothing secures the rows lower inthe stack.

In U.S. Pat. No. 4,777,781, where the compression plate is first raisedto the ceiling, loaders must work under the plate and in front of themachine. This is undiserable.

SUMMARY OF THE INVENTION

An object of the present invention is to disclose an improved tire loadcompression system. Specifically, one object is to make a more simplesystem. The fixture mounts on standard forklifts without any specialattachments. The forklift supplies all operating forces: lift, steeringand hydraulic pressure and controls. Forklifts also have a tiltmechanism to angle the support frame, compression platen and pusherplates to aid in holding the stacks straight while compressing the tiresand to push the compressed stacks of tires together to increase overallload density.

Also, by relying on the weight of the fixture that contacts the tires tocompress the tire stack, the system can utilize a single hydrauliccylinder or other drive mechanism only for driving the fixture above theload of tires. Thereafter, when the upward force is relieved, the weightof the fixture acting through a platen or horizontal shelf above thestack compresses the stack of tires. By choosing the appropriate fixtureweight, one obtains better control of the compression. Also, thedevice's weight can be modified by adding or subtracting weight tochange the compression for different sizes and types of tires.

When using a drive mechanism to pull the fixture downward, the machinecan apply too much force on the tire stack, in which case, some tirescould be damaged. If the device fails to apply enough force, the loaddensity is decreased. Also by relying only on fixture weight asapplicants do, it is unnecessary in the present invention to have acomplex overhead frame pushing against the top of the container to holdthe device in place vertically as it applies force on the tire stack.

Another object of the present invention is to disclose and provide animproved system for removing the platen from between the two adjacentrows of tires. The present invention uses a pusher plate depending fromthe compression platen or shelf to hold several rows of tiresimmediately below the platen. This pusher plate extends downward infront of several rows. That pusher plate is mounted next to the device'ssupport frame, and that frame also secures tires below the pusher plate.

The pusher plate slides in slots in the platen and is pushed against thetires by a hydraulic ram. When the stack is full and the fixture raisesupward to equalize the compression above and below the platen, a rampushes on the pusher plate against the stack of tires. Because the otherside of the hydraulic ram connects to a forklift, and the platen alsodoes not move horizontally relative to the forklift, force on the pusherplate pushes the forklift back, away from the stack of the tires, whichin turn withdraws the platen from between the two adjacent rows.

Another feature of the present invention is the use of a hinged pusherplate above the platen. That hinged plate is the top-most part on thefixture. By pivoting that pusher plate down so that it lies horizontallyon the top of the platen, the forklift can raise the platen almost tothe container ceiling. Then, when the fixture lowers to compress thelower rows of tires and then additional tires are placed above theplaten, the hinged pusher platen can be pivoted vertically and thenlocked. That plate in its locked position holds the tires above theplaten as the platen is withdrawn.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side elevation of the tire load compression fixture mountedon a forklift.

FIG. 2, which was already discussed briefly, shows an end schematic viewof tires loaded in a herringbone pattern in a container.

FIG. 3 is a cross-section of detail 3 in FIG. 1 of the platen.

FIGS. 4, 5 and 6 are side elevations of the load compression system ofthe present invention showing the device at different stages ofoperation within a container.

FIG. 7 is a perspective view of the load compression fixture of thepresent invention.

FIG. 8 is a side view of the upper part of the fixture of the presentinvention with the upper pusher plate in its lower orientation.

FIG. 9 is a view similar to FIG. 8 but with the upper pusher plate inthe elevated, upright orientation.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The exemplary embodiment of the tire load compression fixture of thepresent invention is shown generally at 20 (FIG. 1). The exemplaryfixture mounts on a forklift 10. The forklift is motorized, and travelson front wheels 11 and rear wheels 12 (FIG. 1). A steering mechanism(not shown) allows the forklift to maneuver.

As is conventional, the forklift has a front mast 13 (FIG. 1).Typically, mast 13 has a hydraulic cylinder, which the forklift motorpowers. The mast would connect conventionally to forks. The presentinvention removes those forks and attaches instead fixture 20 (FIG. 1)of the present invention. A hydraulic cylinder 14 applies force onfitting 15 on mast 13. By adjusting the distance that arm 16 extends outof cylinder 14, the angle of mast 13 can be changed. This tilt mechanismfacilitates the compression of the tire stack by changing the platen'sangle.

Tire load compression fitting 20 includes a support frame 22 (FIG. 1).Brackets 24 and 26 (FIG. 1 ) attach support frame 22 to mast 13. Theconnection between the support frame and the mast is similar to thatused to attach conventional forks to the mast. A vertical driver 23 inthe form of a hydraulic cylinder (schematically shown) in mast 13connects to a carriage in the mast to which the braces are attached. Thehydraulic cylinder can raise and lower support frame 22. As will beappreciated, because other items of the compression fixture 20 are fixedvertically to support frame 22, fixture 20 moves vertically with supportframe 22.

In the exemplary embodiment, support frame 22 is formed from two plates32 and 33 of 1/2" (1.3 cm) thick, 50" (1.3 m) tall and 6.5' (2 m) widesteel plate. Internal C-channels (not shown) and edge C-channels 36 and37 (FIG. 7) separate and hold plates 32 and 33 together. In theexemplary embodiment, these and other steel pads are welded together.Edge C-channels 36 and 37 also close the sides of support frame 22.

A compression platen extends in a horizontal plane in a direction awayfrom the fork lift 10. In the exemplary embodiment, the rear ofcompression platen 30 is welded to the top of support frames 32 and 33(FIGS. 7-9). Platen 30 extends forward (i.e., away from the forklift 10)of support frame 22.

Compression platen or shelf 30 in the exemplary embodiment is formed of1" (2.5 cm) thick steel, approximately 7' (2.1 m) wide and 401/2" (1 m)deep. The platen's width is about 8" (20 cm) less than the inside widthof a conventional shipping container. The spacing, about 4" (10 cm) oneach side of the platen and the container walls, allows the forkliftsome maneuvering within the container. The resulting available spacebetween the edges of the platen and the container walls is narrow enoughto prevent a tire to pass between the platen's side edges and thecontainer side walls. Therefore, all tires in the stack below the platenwill be compressed.

Platen 30's front edge 40 is tapered (FIG. 7) for a smooth transitionwhen the platen is removed from the tire stack (as discussed below).Platen 30 also has rounded corners 41 and 42 to eliminate pointed edges.

Platen 30 in the exemplary embodiment also has smooth top and bottomplastic sheets 38 and 39 (FIG. 3). The plastic--preferably polyethyleneor other low friction plastics--reduces friction from the tires pushingupward on the bottom and downward from the top of platen 30. Withoutfriction-reducing plastic, the friction between the tires and the platenwill be increased, but the device still will function well withoutplastic.

Quarter inch (0.6 cm) thick plate steel sheet 44 spans the bottom ofsupport plates 32 and 33 of support frame 22. Additionally, half of a 3"double, extra strong pipe 46 is welded to the bottom of plate 44 (FIG.1). The pipe's rounded bottom protects the tires being compressed fromcatching on the bottom of support frame 22. Also the rounded bottom canrest on the floor of a container, the warehouse floor or parking lot andprevents damage both to the support frame and to the floor or lot.

A pusher plate extends in a plane perpendicular to the plane of thecompression platen. The pusher plate extends both above and belowcompression platen 30. In the exemplary embodiment, pusher plate 50comprises lower pusher plate 51 and upper pusher plate 53. Also in theexemplary embodiment, lower pusher plate 51, which extends below platen30 in the exemplary embodiment is 6.5' (2 m) wide and 1.5' (0.5 m) high.Lower pusher plate 51 also is formed of (1/2"cm) steel. Bottom corners54 and 55 of lower pusher plate 51 (FIG. 7) are radiused to eliminatesharp corners. Compression platen 30 in its exemplary configuration hastwo spaced parallel slots, 56 and 57 (FIG. 7).

The top of lower pusher plate 51 is welded to slide fitting 58 (FIGS. 8and 9). Slide fitting 58 is formed of 1" (2.5 cm) thick ×8" (20 cm) wide×15" (38 cm) long steel plate. Brace 60 (FIGS. 8 and 9) is welded to thefront face of lower pusher plate 51 and to the bottom front of slidefitting 58.

Plate 61 has four generally evenly spaced, tapered screw holes 62 in tworows (FIG. 8). These holes are aligned with threaded bores 64 throughslide fitting 58. Taper head bolts 66 pass through tapered screw holes62 and slot 57 (and slot 56) and are threaded into threaded bores 64(FIG. 8). The bolts, therefore, secure plate 61 and slide fitting 58together. Although not shown, small plastic sliders, approximately thewidth of each slot 56 and 57, are be interposed between plate 61 andslide fitting 58 within each slot. The sliders are provided with boresthrough which bolts 66 pass.

A horizontal driver, which includes hydraulic cylinder 70 attaches tothe back of front plate 33 of support frame 22 (FIGS. 8 and 9). FIG. 7shows a second hydraulic cylinder 71, which also is part of thehorizontal driver. Bolts 73 secure cylinder fitting 72 to plate 33.Piston rod 74 moves into and out of cylinder 70 through hydraulicforces. Piston rod 74 extends through openings 75 and 76 in frontsupport plate 33 and lower pusher plate 51 and threads into brace 60 tosecure piston rod 74 to the brace. As discussed in more detail below,movement of piston rod 74 by cylinder 70 acting on brace 60 moves lowerpusher plate 51. Hydraulic line 80 (FIG. 1) which connects to thehydraulic system (not shown) of forklift 10 controls the movement ofpiston rod 74 relative to cylinder 70.

Upper pusher plate 53 is hinged relative to plate 61 (FIGS. 8 and 9). AsFIG. 7 shows, pusher plate 53 is the same 7' (2.1 m) width as wide ascompression platen 30. Side edges 83 and 84 of upper pusher plate 53 aretapered inward. A 6' (1.8 m) hinge 88 is attached to plate 61 and upperupper pusher plate 53 (FIGS. 8 and 9). Another hinge 96 (FIGS. 8 and 9),which is attached to upper pusher plate 53, also attaches to brace 100.Brace 100 is formed of 1/4" steel plate, which is approximately 2.5"(5.6 cm.) wide near hinge 96, and it tappers to about 2.5" (6.3 cm.)wide at its opposite end. The brace is about 6.5" (16.5 cm) long.

Hinge 88 permits upper pusher plate 53 to pivot between a generallyvertical position aligned with lower pusher plate 51 (FIG. 9) and anunaligned position, horizontal in the exemplary embodiment (FIG. 8).When the operator wants to release upper plate 53 to its uprightorientation, he or she manually pivots the pusher plate about hinge 88to that position. The operator then pivots brace 100 about hinge 96 andplaces the opposite end against stop 102. Stop 102 holding brace 100resists any force backwards (to the right in FIG. 9) on upper pusherplate 53.

To release upper pusher plate 53 from the upright position, the operatorpivots the pusher plate forward somewhat to allow brace 100 to bereleased from stop 102. Upon its release, upper pusher plate 53 is thenrotated clockwise to the horizontal position (FIG. 8). Brace 100 also isrotated about hinge 96 to be aligned with upper pusher plate 53 (FIG.8). As that figure shows, pusher plate 53 does not extend upwardsignificantly above compression plated 30. As will be discussed below,this arrangement allows the compression platen to be raised almost tothe top of a container without interfering with the ceiling of thecontainer.

The rear wall 32 of support frame 22 is provided with two steps orplatforms 104 on either side of support frame 22 (FIG. 9). The platformsallow workers to stand on the support frame 22 whether the frame is nearthe ground or in an elevated position.

The tire compression device of the present invention operates asfollows. Tires are conventionally loaded in a herringbone pattern withincontainer 108 (FIG. 2). Container 108 has a rear wall 110 (FIG. 4), sidewalls 111 and 112, a ceiling 113 and a base 114. Each container wall isabout 7'8" to 8'2" (2.3 m to 2.5 m) wide. The rear end of the container(right side in FIG. 4) has rear doom (not shown) allowing access intothe container.

During normal loading operation, forklift 10 is not in container 108.This is advantageous because the loading crew stacks tires in thecontainer before the forklift enters the container. As a safety feature,the crew (except the forklift operator) also is away from the tires asthe tires are being compressed. Tires are carried or rolled towardcontainer back wall 110. A first tire 120 (FIG. 2) is propped againstone of the side walls (in this case wall 112) and against rear wall 110.A loader then puts the next tire 121 against the first tire 120 andrepeats the process with tire 122 and other tires until tire 123 reachesthe other side wall 111. Those tires form a first row 124. As analternative loading method, the first tire may be laid horizontallyagainst sidewall 112 and rear wall 110. The adjacent tire is then leanedpartially over the first tire. The remaining tires in the first rowassume approximately the same angle as the second tire.

After the loader completes the first row 124, he or she then begins thesecond row 126. First, tire 128 is placed perpendicular to the tires inthe first row 124. Tire 129 is then placed over tire 128, and the tireloading process is repeated until tire 130 reaches end wall 112. In asimilar manner, row 132 is added. These rows build a first stack 134(FIG. 4) along rear wall 110 of container 108.

When the herringbone pattern reaches close to ceiling 113, the loadersleave the container, and an operator drives forklift 10 into container108. After first stack 134 is loaded to the top of the container, it iscompressed. The compression operation in the drawings is shown acting ona second stack 136, which is stacked in a similar manner to stack 134.In FIGS. 4-6, stack 134 is already compressed, and stack 136 is about tobe compressed in the following manner. After the top row of tires instack 136 reaches just below the ceiling 113, an operator drivesforklift 10 into container 108. The mechanism within mast 13 for raisingthe fixture raises the fixture until it is very close to the ceiling inthe FIG. 4 position. Upper pusher plate 53 is in its horizontalorientation (FIG. 8). Because that position allows compression platen 30to be very close to ceiling 113 without any part of fixture 20interfering with the ceiling, the tires can be loaded almost to theceiling.

In FIG. 5, the weight of fixture 20 is released to compress the tires insecond stack 136. The fixture weights between 3,500 and 4,000 lbs.(1,590-2,040 kg), and it compresses the tires to about half theiroriginal volume. The fixture can achieve different compression ratiosthrough changes in its weight. Its is anticipated that the user couldadd or remove additional weight to allow for the proper amount ofcompression for each type and size of tire. FIG. 5 shows approximately50% reduction in volume as the fixture comes down from the 9' (2.7 m)ceiling approximately 4.5' (1.4 m).

The loader begins loading additional tires, e.g., tire 138 (FIG. 5) in aherringbone pattern above platen 30. When the stack reaches ceiling 113,the operator or loader then pivots upper pusher plate 53 to its upright(FIG. 8) position. The lift cylinder in mast 13 moves fixture 20 upward,against the force of gravity, to relieve some of the compression on thetires below platen 30 and to compress the tires above the platen untilthe upward and downward forces on the platen are approximately equal.

After the vertical forces are balanced, the platen is then removed frombetween adjacent rows of tires. To accomplish removal, hydrauliccylinders 70 and 71 are activated. The piston rods 74 acting on brackets60 moves pusher plate 50 (i.e., upper pusher 53 and lower pusher plate51) to the left (FIG. 9). Because upper pusher plate 53 is in itsupright orientation, it too pushes against the first row of tires aboveplaten 30.

While cylinder rods 74 push the pusher plate 50 to the left, the brakesof forklift 10 are released. The pusher plate, which acts against thetires, remains stationary relative to the tires as compression platen 30withdraws from between the two adjacent rows of tires. The compressionplaten's movement pushes forklift 10 rearward (FIG. 6) until the tiresrelease the platen. Hydraulic cylinders 70 and 71 then retract pusherplate to its right-most orientation. The driver then drives forklift 10out of container 108, and loaders begin stacking a third stack of tiresin a similar manner.

As FIG. 4 shows, as the tires in stack 136 are being compressed, thelower pusher plate 51 and front wall 33 of support frame 22 are close toor against the rows of tires immediately below platen 30. This preventsthe tires from bowing outward or falling out of the stack. It alsopushes the stacks of tires closer together horizontally, which increasesthe overall tire load density.

As numerous modifications and alternate embodiments will occur to thoseskilled in the art, it is intended that the invention is limited only interms of the appended claims.

We claim:
 1. A device for compressing tires in a shipping containercomprising:a. a support frame attached to a fork lift; b. a fixtureattached to and moveable vertically upward along the support frame andbeing released so that the fixture's weight compresses any tires belowthe compression platen, the fixture comprising:i. a compression platenextending in a general horizontal plane, the compression platen having aslot extending through the compression platen; ii. a pusher plateextending in a plane perpendicular to the plane of the compressionplaten, the pusher plate having a lower pusher plate depending from thecompression platen and an upper pusher plate extending above thecompression platen, the pusher plate being mounted in the slot of thecompression platen for movement along the slot of the compressionplaten; iii. the fixture being of sufficient weight to compress tiresstacked below the compression platen; and c. a horizontal driverconnected to the pusher plate for pushing the pusher plate away from thesupport frame.
 2. The device for compressing items of claim 1, whereinthe upper pusher plate is mounted for pivoting between an uprightorientation aligned with the lower pusher plate and an orientation thatis angled to the lower pusher plate.
 3. A fixture for compressing tiresin a shipping container, the fixture being attachable to a vehicle, thefixture comprising:a. a compression platen extending in a generalhorizontal plane, the compression platen having a slot extending throughthe compression platen; b. a pusher plate extending in a planeperpendicular to the plane of the compression platen, the pusher platehaving a lower pusher plate depending from the compression platen and anupper pusher plate extending above the compression platen, the pusherplate being mounted in the slot of the compression platen for movementalong the slot of the compression platen; c. the fixture weighing atleast 3,500 pounds.
 4. The fixture for compressing tires of claim 3,wherein the upper pusher plate is mounted for pivoting between anupright orientation aligned with the lower pusher plate and anorientation that is angled to the lower pusher plate.
 5. A device forcompressing items in a shipping container comprising:a. a vehicle; b. asupport frame attached to the vehicle; c. a fixture attached to andmoveable vertically along the support frame, the fixture comprising:i. acompression platen extending in a general horizontal plane, thecompression platen having a slot extending through the compressionplaten; and ii. a pusher plate extending above and below the compressionplaten and in a plane perpendicular to the plane of the compressionplaten, the pusher plate being mounted in the slot of the compressionplaten for movement along the slot of the compression platen; d. ahorizontal driver connected to the pusher plate for pushing the pusherplate away from the support frame; and e. a vertical driver on the forklift and connected to the fixture for moving the fixture upwardsrelative to the support frame and releasing the fixture so that thefixture's weight compresses any tires below the compression platen. 6.The device for compressing items of claim 5, wherein the portion of thepusher plate that is below the compression platen is a lower pusherplate depending from the compression platen and the portion of thepusher plate that is above the compression platen is an upper pusherplate extending above the compression platen, the upper pusher platepivoting between an upright orientation aligned with the lower pusherplate and an orientation that is angled to the lower pusher plate. 7.The device for compressing items of claim 6, further comprising a stopon the upper pusher plate securing the upper pusher plate in the uprightorientation.